Package org.apache.flink.table.typeutils

Class FieldInfoUtils

  • @Internal
public class FieldInfoUtils
extends Object
    Utility methods for extracting names and indices of fields from different TypeInformations.

    • Method Detail

      • getFieldsInfo

        public static <A> FieldInfoUtils.TypeInfoSchema getFieldsInfo​(org.apache.flink.api.common.typeinfo.TypeInformation<A> inputType)
        Returns a FieldInfoUtils.TypeInfoSchema for a given TypeInformation.
        Type Parameters:
        A - The type of the TypeInformation.
        Parameters:
        inputType - The TypeInformation to extract the mapping from.
        Returns:
        A description of the input that enables creation of a TableSchema.
        See Also:
        FieldInfoUtils.TypeInfoSchema

      • getFieldsInfo

        public static <A> FieldInfoUtils.TypeInfoSchema getFieldsInfo​(org.apache.flink.api.common.typeinfo.TypeInformation<A> inputType,
                                                              org.apache.flink.table.expressions.Expression[] expressions)
        Returns a FieldInfoUtils.TypeInfoSchema for a given TypeInformation. It gives control of the process of mapping TypeInformation to TableSchema (via FieldInfoUtils.TypeInfoSchema).

        Possible operations via the expressions include:

        • specifying rowtime & proctime attributes via .proctime, .rowtime
          • There can be only a single rowtime and/or a single proctime attribute
          • Proctime attribute can only be appended to the end of the expression list
          • Rowtime attribute can replace an input field if the input field has a compatible type. See TimestampType.
        • renaming fields by position (this cannot be mixed with referencing by name)
        • renaming & projecting fields by name (this cannot be mixed with referencing by position)
        Type Parameters:
        A - The type of the TypeInformation.
        Parameters:
        inputType - The TypeInformation to extract the mapping from.
        expressions - Expressions to apply while extracting the mapping.
        Returns:
        A description of the input that enables creation of a TableSchema.
        See Also:
        FieldInfoUtils.TypeInfoSchema

      • getFieldNames

        public static <A> String[] getFieldNames​(org.apache.flink.api.common.typeinfo.TypeInformation<A> inputType)
        Returns field names for a given TypeInformation.
        Type Parameters:
        A - The type of the TypeInformation.
        Parameters:
        inputType - The TypeInformation extract the field names.
        Returns:
        An array holding the field names

      • getFieldNames

        public static <A> String[] getFieldNames​(org.apache.flink.api.common.typeinfo.TypeInformation<A> inputType,
                                         List<String> existingNames)
        Returns field names for a given TypeInformation. If the input TypeInformation is not a composite type, the result field name should not exist in the existingNames.
        Type Parameters:
        A - The type of the TypeInformation.
        Parameters:
        inputType - The TypeInformation extract the field names.
        existingNames - The existing field names for non-composite types that can not be used.
        Returns:
        An array holding the field names

      • validateInputTypeInfo

        public static <A> void validateInputTypeInfo​(org.apache.flink.api.common.typeinfo.TypeInformation<A> typeInfo)
        Validate if class represented by the typeInfo is static and globally accessible.
        Parameters:
        typeInfo - type to check
        Throws:
        org.apache.flink.table.api.ValidationException - if type does not meet these criteria

      • getFieldIndices

        public static int[] getFieldIndices​(org.apache.flink.api.common.typeinfo.TypeInformation<?> inputType)
        Returns field indexes for a given TypeInformation.
        Parameters:
        inputType - The TypeInformation extract the field positions from.
        Returns:
        An array holding the field positions

      • getFieldTypes

        public static org.apache.flink.api.common.typeinfo.TypeInformation<?>[] getFieldTypes​(org.apache.flink.api.common.typeinfo.TypeInformation<?> inputType)
        Returns field types for a given TypeInformation.
        Parameters:
        inputType - The TypeInformation to extract field types from.
        Returns:
        An array holding the field types.